Valve as the main control unit in the petrochemical industry fluid conveying system, the sealing performance is good or bad will have a great impact on the energy saving effect of the whole system, completes the valve sealing structure improvement is more important. Based on this, this paper first on the influence factors of valve sealing structure and main points of application are discussed, then the valve sealing structure improvement measures and explore the improvement effect, hoping to deepen the exploration from the theory level, play a enlightenment role for the actual work.
Valve in use process is easy to appear problem is strength and seal failure, it is inevitable that the energy resources waste, also prone to security issues. The structure of the valve sealing improvement work is the key to improve the quality of the valve application work, from the theoretical level to deepen research can help the actual valve sealing structure to improve operations.
1 the influence factors of valve sealing structure and main points of application
1.1 the influence factors of valve sealing structure analysis
Valve seal degree is need to combine the types and properties, the combination of the valve is sealed and the valve materials and equipment and technology has a direct relationship, any link appeared quality problem, it will inevitably affect the quality of the valve application . Combined with the scientific design standard, sealing structure to design into a cone or a sphere, but peace face seal structure comparison, this seal structure will has many adverse effects, prone to scratches on sealing surface, and cause the difficulty of the maintenance process there are many, this also is easier to increase the production cost, etc., market sales also can produce very big effect.
Valve sealing surface design for cone or sphere, there will be adverse factors, take plane sealing design, the valve stem and valve cover sealing surface from cone shape became surface contact style, this way less constrained, device and equipment accuracy can get security, processing is relatively easy to some. Valve using time length and number of times presents a proportional valve switch, maintenance aspects are relatively easy to .
1.2 the valve sealing structure application points
Application of valve sealing structure, want to notice to greater attention from several aspects, can't let the valve in the opening smaller work conditions, the start of the needle valve is relatively slow. So when opening the little throttling interval is relatively small, more appropriately expand the locking mechanism pitch, increasing the speed and the opening of needle valve lift, the work of opening will further increase, can effectively extend valve life cycle.
Practical application of the valve seal structure, the use of medium temperature for valve cycle is easier to impact, high medium temperature is easier to shorten valve life, in the process of concrete use, shall not apply as far as possible the valve working under high temperature and medium, pressure relief valve to increase cooling device, it can effectively extend valve life cycle. To avoid impurities into the among them, this will affect the service life of the needle valve . In addition, the need to periodically clean and filter high pressure medium, add the liquid need to adopt filter implementation, using more to use cycle shorten appropriately, to do a good job of cleaning tank, etc., only got full attention from these aspects, to ensure quality of valve sealing structure of the application.
2 the valve sealing structure improvement measures and improve the effect
2.1 the valve sealing structure of improvement measures
Valve seal structure improvement can improve the performance of the valve seal structure, industrial producers red damage of valve sealing surface appear through the corresponding ong hair repair. Commonly used grinding method, the status of the extent of the damage of valve sealing surface small is more applicable, add appropriate abrasives grinding stones and sand paper can grinding operation. Can also through deep repair method, mainly adopt the way of turning processing to carry on the processing, the application of this method of time demand is high, time-consuming, and the hardness of materials after deep processing and the quality will change, structure also can appear some changes .
Valve seal structure to improve operations, to fully pay attention to the scientific application of method, the valve sealing surface is hard material structure, less easy to fix, in to improve the process, can be full thread form small bolt welding parts, in the center of the valve plate face by ptfe plate, can also be supported by rubber and equal seal, valve seal measure the gasket custom on the valve core, can washers and nut pressure modulation device, which can guarantee the seal and the corresponding valves used jointly.
In addition, improvements to the butterfly valve sealing structure is also more important, this need accordingly. The butterfly valve sealing structure adjustment look to a state of compression, the sealing effect is relatively good, medium in the process of reverse pressure to butterfly plate, the sealing effect is affected by the corresponding, especially large diameter valve problem is more obvious. In the process of valve sealing structure improvement, requires greater attention from structural design, to be able to guarantee two-way type metal sealing butterfly valve sealing good results. And the body of the valve shaft under fixed require relatively tight transition fit, minimize cooperate with clearance, change the butterfly plate stress points in time, this can effectively reduce the compression of butterfly plate deformation. Moreover, through the double eccentric spherical structure and elastic thin-walled metal ring structure, implementation and elastic compensation, compensation for the displacement of the valve in the open, take out completely and not cause abrasion using stainless acid-resistant steel, avoid rust. Butterfly look when valve is closed to the pressure, will make the displacement of elastic metal ring inside diameter, specific pressure value will rise, but can guarantee the lowest sealed pressure value, improve the effect of reverse seal.
2.2 the valve sealing structure improvement effect
From the improvement of the valve seal structure effect to see, through the actual application, has a good application effect, will not affect valve flow medium velocity, has a good sealing effect, for the damage of valve sealing surface can't repair the problem has been effectively solve. Valve internal leakage, by sealing pads to replace the wear can solve practical problems, is has a good economical effect on cost. Soft seal and hard seat sealing surface can form sealing surface, by improving the rigid hard seal before become a combination of hard and soft seal, so it can effectively increase the area of the seal. Seat sealing surface appear small damage, for regulating valve screw open degree of compaction soft gasket can get compensation, through the application of the improved valve sealing structure, maintenance is more convenient, cost is low.
Improvements to the structure of sealing butterfly valve, also have a good effect, and guarantee the quality of the structure design, prolong the service life of the two-way metal sealing butterfly valve, also can reduce the unit using the valve replacement frequency, so it can effectively reduce from the whole cost, reduce working intensity, improve work efficiency as a whole.
In order to guarantee the use effect of the valve sealing structure, improve the protective measures are necessary. This would require the security valve plate welded bolt length is not too long, or it will cause the phenomenon of sealing surface overhead, the sealing effect will be affected. Choose appropriate adjust pad, thickness is slightly less than or equal to the steps of the valve sealing surface height, make the gasket and valve sealing surface can fit tightly, in the same plane. More fluid conditions of use, give full consideration to avoid medium corrosion and high temperature deformation factors affect the use effect of the valve seal structure. The damage of the seat sealing surface appears more serious, the seat to scrap processing, by improving the valve core can seat to form a complete set of application and the specifications. Regulating valve should be mark which can effectively avoid, fierce on fierce off, can't affect the service life of the seal. Through the application of the improved method can greatly improve the effect of the use of the valve seal structure, the streamline type structure simple cut-off valve is applicable, fluid structure requirements of different types of valves cannot be used.
In short, to improve application of the valve sealing structure, to improve the quality of the application of the valve. Valve applications to do a good job in the corresponding protection which is important way to prolonging the service life of the valve. Through in this paper the improvement of the valve sealing structure, and the application of relevant to explore, to the improvement of the valve seal structure in theory have more understanding, so as to provide reference for the actual improvement work. Improve work smooth implementation can protect the safety of the valve work, must from the perspective of security to do a good job of corresponding improvement.